Rimonabant patent failure in India could scupper US approval

Generic versions of sanofi-aventis Acomplia weight-loss pill, which failed to win FDA approval in the US over increased risk of suicide, continue to be sold in India

Generic versions of sanofi-aventis Acomplia (rimonabant) weight-loss pill, which failed to win FDA approval in the US over increased risk of suicide, continue to be sold in India.

Cipla and Ranbaxy are taking advantage of a loophole in Indian patent laws and are selling their own brand versions Slimona and Defat. The pills are sold off prescription in the region for as little as USD 0.12.

PMLive reported earlier in the year that S-A had not bothered to protect the patent for rimonabant in India, as it did not see the region as a major money maker for the drug. Now, the legal window for patent protection in India has been closed, so the French company no longer has any legal recourse to stop generic copies from being sold there.

The Indian generic market for rimonabant has inadvertently provided the FDA with an opportunity to study the effects of the drug. If the rimonabant copies lead to increased levels of suicide in those taking the drug, there is very little chance S-A will win US marketing approval.

Analysts add that S-A has no credible pipeline drug to replace the lost sales of Acomplia and after the FDA rejected the treatment on 29 June 2007. The USD 3bn in annual sales S-A had hoped for the drug have thus been negated.

S-A's shares fell EUR 0.76 to rest at EUR 60.59 in am trading on 9 August in Paris, and have dropped 14 per cent since a high of EUR 71.66 recorded on 31 May 2007.